Collision detection is the determination of whether or not two or more entities make contact with each other during gameplay.

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Deactivate keyboard input on collision

I'm creating an online-canvas-game with a tank as player object. Now I have several structures in my canvas, that shouldn't be able to be overdriven by the tank... My solution is to detect the ...
2
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2answers
447 views

How can I optimise collision checks for a large number of AI units?

Let's say I got 100 Orcs in my 3D world and they all aim to kill each other. That means for every 1 Orc I have to check for collision with the 99 others. That will give me 99^2 which is about 10,000! ...
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8answers
6k views

How do I prevent my platformer's character from clipping on wall tiles?

Currently, I have a platformer with tiles for terrain (graphics borrowed from Cave Story). The game is written from scratch using XNA, so I'm not using an existing engine or physics engine. The tile ...
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1answer
565 views

Do I need to roll my own polygon segmentation algorithm to automate Box2d body creation from a tile map?

Before re-inventing the wheel I figured I'd ask: I'm working on a tile-based 2d-maze level generator for cocos2d + box2d. The idea is: I'm using one of the well-known graph traversal algorithms to ...
4
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2answers
1k views

Sliding collision response

I have been reading plenty of tutorials about sliding collision responses yet I am not able to implement it properly in my project. What I want to do is make a puck slide along the rounded corner ...
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2answers
1k views

Issue with removing sprites on collision

I'm trying to make a very simple collision detection procedure just for test purposes. The problem is with the send/receive information between functions I have these lines on the update method ...
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2answers
1k views

OpenGL : Suggestion on handling collision detection and vertex data?

I was thinking how to do collision detection in my OpenGL application and came to conclusion that I should keep two copies of my geometry data. 1)First copy : Only for OpenGL rendering purposes.This ...
2
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2answers
511 views

Snake game - collision detection causing new position of apple to be rendered multiple times

I have a collision method implemented through the use of slick2d. When ever the snake collides with the apple, it causes the apple to be rendered in multiple places before the snake moves further ...
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2answers
420 views

Collision, then what?

I know how to check collision for example 2 spheres. But my question is how do I use the collsion response in a good way? How do I make my character unable to walk in to the Sphere? I've got to the ...
4
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1answer
2k views

Collision with tile corners/seams in 2D platformer

There seems to be a lot of somewhat related questions answered already, but none I read answered my exact problem. I have a 2D platformer whose world is made entirely out of tiles that are in a ...
0
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1answer
146 views

CCSprite x and y comparison

I have 2 CCSprites and I want to tell if their x and y are equal I tried this: if(sam.position.x == tom.position.x && sam.position.y == tom.position.y){ NSLog(@"Hooray!"); } Although I do ...
2
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1answer
277 views

When is it the right time to start teaching collision detection?

I and a friend of mine started a game development club in our school two months ago and everything is going well for now. We are following McKesson's tutorials which I find comprehensive and ...
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2answers
218 views

C# XNA 4.0 Rectangle Rotation Collision

I can easily rotate my sprite, but how could I rotate my rectangle for my collision (Thinking of using the Separating Axis Theorem, But I have no clue how to apply it) Help or Example would be ...
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4answers
512 views

3D: How how handle like 500 NPC

I'm currently working on a 3D game. My game have like 10 NPC's and a really small world. But if I want to have a larger world with lots of NPC's? I think it's not a good idea to update and check ...
4
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1answer
2k views

How can I convert a 2D bitmap (Used for terrain) to a 2D polygon mesh for collision?

So I'm making an artillery type game, sort of similar to Worms with all the usual stuff like destructible terrain etc... and while I could use per-pixel collision that doesn't give me collision ...
0
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1answer
989 views

Sphere and AABB intersection

I'm looking for an algorithm that will determine if a sphere is in any way touching an AABB or contained within it. Profile results indicate that this specific use is taking up a large percentage of ...
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1answer
131 views

Collision detected on only the latest added tile

I'm making a 2D platformer and I'm using tiles as the ground. I have a Tile class and I'm loading the tiles with the help of a list in the main game class: public static List<Tile> tiles = new ...
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2answers
1k views

What has the most efficient intersection test against an AABB tree - OBB, Cylinder or Capsule?

I'm currently trying to find collisions in 3D between a tighter volume than an AABB and a tree of AABB volumes. I just need to know whether they are intersecting, no closest distance or collision ...
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3answers
2k views

2D AABB vs AABB Sweep : How to calculate hit normal?

I've implemented a 2D AABBvsAABB sweep cast into my game, however, I'm having difficulty calculating the hit normal of the sweep cast. I have the sweep direction, both a and b AABB positions and xy ...
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1answer
257 views

Where in code to for collision? In object class? Mainline code?

Making a simple game in Love 2D framework where if I click on an object then it disappears. Do I check to see if I've clicked the enemy inside a function in the enemy object? Or just in my main.lua? ...
0
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1answer
2k views

GameObject and Components

I am creating a relatively simple game engine in C++ and Qt. I am using Irrlicht for graphics, and as of now, I will not be using any physics or audio libraries. For time's sake, I am using ...
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2answers
520 views

Collisions between moving ball and polygons

I know this is a very typical problem and that there area a lot of similar questions, but I have been looking for a while and I have not found anything that fits what I want. I am developing a 2D ...
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1answer
616 views

3D Collision help

I'm having difficulties with my project. I'm quite new in XNA. Anyway, I'm trying to make 3D game and I'm already stuck on one basic thing. I have terrain made from a heightmap, and an avatar model. I ...
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2answers
1k views

Reflect angle on pong clone [duplicate]

I'm working on collision detection for a pong clone. I've calculated the angle of incidence but I can't find any information on how to specular reflect the angle I found. The code for calculating the ...
0
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1answer
2k views

AS3 hittest with a tweening movieclip, what is the best way?

I'm making a simple game. The character is movable with the arrow keys. The enemies are moving around the screen with a (classic) tween. I want to detect collision between the character and the ...
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3answers
2k views

How can I do fast Triangle/Square vs Triangle collision detection?

I have a game world where the objects are in a grid based environment with the following restrictions. All of the triangles are 45-90-45 triangles that are unit length. They can only rotate 90°. The ...
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1answer
266 views

Collision Detection Efficiency

I've just written my first successful collision detection code, and it works great for a small scene of actors (player + 4-5 obstacles). However, I realize that since it checks every possible ...
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2answers
3k views

Sprite collisions in android andengine

I'm developing a simple game by andengine. I have 10 balls which are moving randomly on screen.i'm importing the balls as picture in sprites.if they move at the same coordinate , they pass though ...
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1answer
254 views

Change of direction after Collision

I am having a pickup image which is moving at random direction and have to change the direction after collision with some tiles, which are a rectangle. I've my own algorithm for detecting the ...
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2answers
969 views

How to calculate the direction a ball must bounce

I have a tile engine I have made. I can detect collision between the ball(the player) and the tiles. When a collision is detected all the colliding tiles are stored inside a list. My question now is, ...
3
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1answer
397 views

SAT and then what?

I am on my way to make another Arkanoid game but this time I decided that I want it a little bit more realistic than just checking intersections between AABB and inverting one vector's component on ...
2
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1answer
832 views

Problems with moving 2D circle/box collision detection

This is my first game ever and I'm a newbie in computer physics. I've got this code for the collision detection and it works fine for BOTTOM and TOP collision.It miss the collision detection with the ...
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0answers
92 views

What is the most effective way to create a set of collision points for an aribitrary mesh?

In my project I am working on automatically deforming an arbitrary mesh with respect to another arbitrary mesh, within the context of user generated content, similar to this deformer being developed ...
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2answers
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Detecting if line crosses rectangle in python. Need speed boost

I am currently writing a top down man vs robot shooter. The game works now, but if I have a decent sized level it runs slowly when you are being chased by robots. While just roaming around it can go ...
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3answers
4k views

Implementing Separating Axis Theorem (SAT) and Minimum Translation Vector (MTV)

I was following codezealot's tutorial on SAT and MTV and trying to implement it myself but I've come a cropper when it comes to getting the correct MTV. Here is my example: (Cue pretty pictures...) ...
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1answer
688 views

C# OpenTK - Getting world coordinates of points that are altered by matrices

I have written a skeletal animation system for a game i am working on. To draw lines that represent a skeleton, i use the GL matrix, and multiply it by each bone a long the body. For example before ...
2
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1answer
323 views

What broad-phase collision algorithms are suited to a static tiled world with dynamic objects of different sizes?

Sorry for this routine question, but I can't think of what broad-phase collision algorithms really work in the following, reasonably standard, setup: 2D tile based world, consisting of objects that ...
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3answers
1k views

How will the velocities of two moving objects change once they collide?

I'm making a small game where things can fly around and collide. Things like boxes and so on. For each object, I have an array of all forces acting upon it, I have it's mass, it's position and it's ...
2
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1answer
564 views

3D RTS pathfinding

I understand the A* algorithm, but I have some trouble doing it in 3D to suit the needs of my RTS Basically, in the game I'm making, there will be agents with different sizes of OBB collision boxes. ...
3
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2answers
957 views

In Box2D, how can I check for bodies within a circle?

I'm trying to sample random positions to find one that is sufficiently far from other bodies. Hence I'd need to test for bodies within a given circle. So far, I've used b2World::QueryAABB around my ...
0
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2answers
4k views

Android Java rectangle collision detection not working

I had been hard coding a collision detection system which was buggy. Then I came across using rectangles for collsion detection. So I put it all in and it does not work, I put a log in and it never ...
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3answers
3k views

Isometric Collision Detection

I am having some issues with trying to detect collision of two isometric tile. I have tried plotting the lines between each point on the tile and then checking for line intercepts however that didn't ...
2
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1answer
515 views

Pixel Collision - Detecting corners

How would I go about detecting the corners of a texture when I use pixel collision detection? I read about corner collision with rectangles, but I am unsure how to adapt it to my situation. Right now ...
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1answer
573 views

2D Tile based Game Collision problem

I've been trying to program a tile based game, and I'm stuck at the collision detection. Here is my code (not the best ^^): void checkTile(Character *c, int **map) { int x1,x2,y1,y2; /* ...
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1answer
295 views

Incorrect results for frustum cull

Previously, I had a problem with my frustum culling producing too optimistic results- that is, including many objects that were not in the view volume. Now I have refactored that code and produced a ...
4
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4answers
970 views

More efficient in range checking

I am going to use a specific example in my question, but overall it is pretty general. I use java and libgdx. I have a ship that moves through space. In space there is debris that the ship can ...
3
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2answers
291 views

Unsure how to decide ray intersection interval

I'm coding an intersection algorithm with AABB, as found here. However, I'm absolutely unsure what to pass in as t0 and t1. The paper states that it's a ray intersection interval, but the only ...
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1answer
512 views

How to handle circle penetration

I've been working on cirlce to circle collision and have gotten the intersection method working correctly, but I'm having problems using the returned values to actually seperate the circles from one ...
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3answers
4k views

Finding the contact point with SAT

The Separating Axis Theorem (SAT) makes it simple to determine the Minimum Translation Vector, i.e., the shortest vector that can separate two colliding objects. However, what I need is the vector ...
52
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6answers
12k views

How does a collision engine work?

How exactly does a collision engine work? This is an extremely broad question. What code keeps things bouncing against each other, what code makes the player walk into a wall instead of walk through ...